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Full text of "A precise method of roasting beef by Elizabeth C. Sprague and H. S. Grindley"

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UNIVERSITY OF ILLINOIS BULLETIN 

Vol. IV MAY 15, 1907 , No. 19 

Entered Feb. 14, 1904, at Urbana, 111,, as second-class matter under act of Congress of July 16, 1894 



CJe Mnitiersiitp ^tutitesi 



Vol. II 



MAY, 1907 



No. 4 



A PRECISE METHOD OF ROASTING 

BEEF 



By 

ELIZABETH C. SPRAGUE^ 

Research Assistant, Nutrition Investigations 

and 

H. S. CRINDLEY, Sc.D., 

Professor of General Chemistry 



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Library Bureau Cat. No. 1137 



Cornell University Library 

TX 749.S76 



A precise method of roasting beef by Eli 




3 1924 003 582 503 




Cornell University 
Library 



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the United States on the use of the text. 



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Vol. II. No. 4. MAY. 1907 



A PRECISE METHOD OF ROASTING BEEF 

By 

ELIZABETH Gi SPRAGUE, 
Keseal-ch Assistant, Niitt-ition Investigations 



H. S, GRINDLEY. Sc D., 

Professor of General Chemistry 



PRICE $1.00 



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OOPTWQHT 1907 

By The UNivKBsmr of Illinois 



A PRECISE METHOD OF ROASTING BEEF 

During the course of extended investigations upon the 
chemistry of the cooking of meats, which are being made in 
the Department of Chemistry of this University, it was found 
necessary to devote some time to the consideration of the prac- 
tical question of the methods of cooking. In preparation for a 
series of experiments to determine the losses and the chemical 
changes which occur when meat is roasted, a few preliminary 
experiments were made to establish certain standards for the 
cooked meat and to determine the conditions necessary to at- 
tain these. 

■The different degrees, designated as rare or underdone, me- 
dium rare, and well done, to which meat may be roasted are at 
present largely matters of individual opinion. What may seem , 
rare to one person, is medium rare to another, while it is not at 
all uncommon to have meat that is actually raw offered as rare. 
The usual household method of attaining these different de- 
grees by allowing for the time of cooking, a definite number of 
minutes for each pound of meat contained in the roast, while 
reliable to some extent, is not sufficiently accurate for careful 
investigations. Under such conditions, considerable variations 
may occur in the degree of cooking, and it has already been 
shown ' that the percentages of the original constituents of the 
raw meat which are removed by cooking depend on this factor. 

DEGREES OF ROASTING 

To almost every one, the sight of a well browned roast or 
steak, somewhat glossy from the mixture of melted fat and 
semi-carbonized substances with which its surface is bathed, 
and well puffed up by the coatraction of the outer fibres is 
much more appetizing than one which is a dull gray in color, 
sodden and shrunken in appearance. As regards the interior of 
the meat, however, there is a greater diversity of taste, ranging 

' U. S. Dept. of Agr. OflBce of Experiment Stations. Bui. 141, p. 93. 

[287] 



from that which prefers that the meat shall have been heated 
only enough to change slightly the color of the interior to that 
which insists upon the disappearance of every trace of pink 
color. There are at least three grades of roasted meat, i. e., rare 
or underdone, medium rare, and well done. 

Ran- (If Uiuh-nloni' Mnif. A cross-section of a rare, roast 
shows the three distinct changes which occur in roasting. One 
of these changes is seen in the center where the dull, bluish 
red characteristic of the raw meat has changed into the bright 
rose red of rare meat. This shades into a lighter pink toward 
the outer portions and changes into a dark gray in the layer 
immediately underlying the outer browned crust. The ideal 
standard for rare meat requires that the larger portion of the 
roast shall have been heated only enough to effect this first 
change to rose red, so that the outer brown crust and the inter- 
mediate gray layer shall be as thin as possible. Under these 
conditions there should be a liberal amount of bright red juice. 

Well-done Meat. If the cooking is continued for a sufficient 
length of time, instead of being distended the meat shrinks 
noticeably, the whole interior is found to have become brown- 
ish-gray in color and the juice is scanty and either colorless or 
slightly yellow. Meat cooked to this degree is said to be well- 
done. 

Medium. Rare Meat. A condition between these two ex- 
tremes is indicated by the term medium rare. In this case, 
sufficient heat has been applied to change the color of the cen- 
ter to a light pink. The gray layer underlying the crust has 
therefore extended considerably toward the center and the free 
juice is smaller in quantity and lighter in color than in the rare 
rneat; 

TEMPERATURE OF THE INTERIOR 

'. The, degrees of cooking indicated above are dependent upon 
the tempierature which is reached in the interior of the meat 
during cooking. A number of investigators have observed the 
degree of heat which penetrated to the interior of various cooked 

[288] 



meats. This varied from 28.75° C. in quickly roasted sausage 
to 98° C. in roasted veal. Wolff hflgel and Hflppe' demonstra- 
ted that the temperature in the interior of large pieces of meat 
never rises to 100° C, even after several hours boiling or roast- 
ing. Such researches as the above, which have been made in 
considerable number had for their object the determination of 
the extent of sterilization which was effected by the process of 
cooking and are not pertinent to the present study. Sir Henry 
Thompson '^ also ascertained the maximum temperature attain- 
ed in meats cooked by various methods and found that how- 
ever thoroughly the meat had been cooked the mercury never 
rose above 185° or 187° F. (85.5° -86° C). It was generally 
a little below this limit. 

Strohmer^ says of the juice pressed from cooked meat that 
"if it is a clear red, the temperature was probably between 50° 
C. and 60° C, but not exceeding 65° C. Between 70° C. and 
72° C. the color of the juice changes to brownish red, and be- 
tween 75° C. and 80° C. to yellow." Liebig* is quoted as au- 
thority for the following: "When a watery infusion of meat 
is heated to 133° F. (56° C), flakes of whitish matter separate. 
These flakes are albumin. When the temperature is raised to 
158° F. (70° C.) the coloring matter of the blood coagulates 
and the liquid which was originally tinged red by this substance 

is left clear and almost colorless Beef or mutton 

cannot be said to be sufficiently roasted until it has acquired 
throughout the whole mass a temperature of 158° F., but. poul- 
try may be well cooked when the inner parts have attained a 
temperature of from 130° to 140° F. (55° to 60° C). This de- 
pends upon the greater amount of blood which beef and mutton 
contain." Yeo^ on the other hand makes the following state- 
ment. "If the temperature of the interior of the joint does not 
rise above 130° F. (55° C.) it remains reddish, blood tinged, and 

> Ostertag- Wilcox' a Handbook of Meat Inspection, p. 843. 

'' Food and Feeding, p. 96. 

- Mitchell's Flesh Foods, p. 214. 

< Mrs. Beeton's Household Management, p. 267 to p. 313. 

5 Food in Health and Diseases, p. 159. 

[289] 



'under-dque.' For beef, mutton, and game this temperature is 
sufficient and gives the tenderest meat and the best flavored, 
but for veal and poultry a higher temperature, 157° F. to 160° 
F: is jieeded." 

J. H. Milroy^ found that at 50° C. from 45.95 per cent to 

55.10 per cent of the albuminous matter of fresh beef was co- 
agulated; at 60° C. from 64.37 percent to 74.47 percent; at 70° 
G. from 90.66 per cent, tb 91.01 per cent; and at 80° C. from 

99.11 per cent to. 100 percent. 

From this it: Will be seen that one-half of these substances 
is coagulable below 50° C. (122° F.) and practically all of them 
between 70° C. and 80° C. (154° to 176° F.). At the latter tem- 
perature, oxyhaemoglobin undergoes a decomposition^ which 
probably marks the disappearance of the last trace of red in the 
juice. 

These observations suggested a method of determining the 
degree of cooking which had been reached in a roast. So many 
factors affect the results obtained by this mode of cooking, e. g., 
temperature of oven, size and shape of roast, kind and quality 
of meat, and so forth, that no satisfactory rule has as yet been 
formulated for this process. Knowing the temperature of the 
oven, one may be guided somewhat by the time of cooking, but 
oven heat is variable and as yet no oven thermometer suitable 
for common use has been devised. Moreover under apparently 
identical conditions of cooking, different results have been ob- 
tained. 

Even after long experience, little reliable information can 
be gained from the appearance of the outside of the meat. 
Though a roast may, when judged by external appearances 
seem to be sufficiently cooked, it may prove very much under- 
done when- out. The roasting of beef seems to the average 
housekeeper to contain many elements of chance, and her anxi- 
ety is seldom relieved until the carver reveals the condition of 
of the interior of the roast. This anxiety has weighed so heav- 



' Archiv. f. Hyg., 1895, XXV, p. 154. 
2 Mitchell's Fleah Foods, p. 37. 

[R90] 



ily upon the minds of some cooks that they have been heard to 
declare that they would rather prepare all the rest of the din- 
ner than to toast the meat. 

Therefore, a method of knowing the condition of the inte- 
rior of the meat, regardless of its external appearance, might 
prove of considerable help, especially to the inexperienced 
housekeeper. It seemed that such a method might be found 
by applying the foregoing principles. Since the degree of cook- 
ing depends upon the extent of the coagulation of the soluble 
proteids of the meat, it should be possible to control the cook- 
ing by observing the temperature of its interior during the proc- 
ess. The range of the inner temperature of the cooked meats 
seemed to be from 50° C. for rare meat, at which about half of 
the soluble proteids become insoluble, to 80° C. for well done 
meats when practically all of these constituents are coagulated. 
In order to test this theory a few experiments were performed 
by the writers in this laboratory. 

PEELIMINARY COOKING EXPERIMENTS 

Four single, short rib roasts of beef containingthe bone were 
used in these experiments. These were as nearly as possible 
of the same size, degree of fatness, and so forth. It was the 
purpose of these experiments to compare the physical condi- 
tion of the meat cooked under the same conditions, until the 
temperature in the center of the roasts reached respectively 
50° C.,60°C., 70°C., and80°C. 

Each roast was placed upright upon the rack of an open 
dripping pan, the fat side being uppermost. An incision was 
made to' its center with a sharp, narrow-bladed knife, and a 
short chemical thermometer, registering 100° C, inserted in 
such a way that the bulb was as nearly as possible in the cen- 
ter of the large muscle of the roast. It was then placed in an 
oven at a temperature of 249 ° C. (450 ° F. ) . This temperature was 
maintained for fifteen minutes to sear the meat thoroughly 
and then reduced to 193°C. (380° F.) for the remainder of the ' 
time of cooking. The meat was removed from the oven when 

[291] 



the thermometer in the center of the roast registered the de- 
sired degree, allowed to stand at the room temperature for from 
thirty to forty-five minutes, then placed in a tightly covered 
glass sample jar over night. In the morning it was cut through 
the center, the physical condition noted, and a water color paint- 
ing made. 

RISE OF TEMPERATURE AFTER REMOVAL FROM OVEN 

The first roast was removed from the oven when the ther- 
mometer in the meat registered 60° C. (140° F.). After removal 
from the oven the temperature continued to increase slowly 
for ten minutes, at the end of which time it registered 64.5'^ C. 
(148° F.). A similar increase in temperature occurred in each 
case, except in that of the roast cooked well-done, when the 
temperature remained stationary after the meat was removed 
from the oven. 

On account of this rise it was found diflBcult to carry the 
temperature to exactly the degree required, but the final fig- 
ures do not differ greatly from the desired degrees. The tem- 
peratures registered in the meat when removed from the oven 
and the subsequent rise in temperature are tabulated with other 
data below in Table I. 

TABLE I. — Time op Cooking and Temperature of Interior of Single, Short- 

HiB Roasts. 









Time of cooking. 


Innerte mperature. 




"o 


Weight 

of 
roast. 


Total. 


Rate 

per 

pound 


When 

removed 

from 

oven. 


Maxim'm 
reached 

after 
removal. 


No. 

degrees 

rise after 

removal. 


Condition of 
cooked meat 


o 

12; 


Lbs. 


Ozs. 


Hrs. 


Mina. 


Mins. 


°C. 


°F. 

116 
140 

152 

174 


°C. 

53.5 
64.5 

69.0 

79.0 


°F. 

128 
148 

156 

174 


"C. 

7.5 
4.5 

2.6 


°F. 




1 

2 
3 
4 


4 
4 

3 

3 


4.25 
2.75 

0.25 

5.00 


■ 1 

1 

1 
1 


10 
20 

25 

40 


16.3 
19.2 

28.2 

30.4 


46.5 
60.0 

66.5 

79.0 


12 
8 

4 


Very rare. 
Medium, verging on 

rare. 
Medium, verging on 

well-done. 
Well-done. 



[292] 



9 

It will be observed that the rise of temperature was great- 
est when the temperature of the meat as taken from the oven 
was lowest, and that this rise decreased as the temperature of 
the interior increased until at 79° C. (174° F.)' there was no rise. 
The rise of temperature after removing from the oven therefore 
would seem to depend partly upon the difference in tempera- 
ture between the outside and the inside of the meat, i. e., the 
greater the difference in temperature, the greater will be the 
rise. 

In the case of one roast which is not included in the table, 
an attempt was made to over-cook the meat very much by rais- 
ing the inner temperature to 100° C. (212° F.). Although the 
roast was thinner than usual, at the end of one and one-half 
hours the inner temperature was only 82° C. (180° F.) and at 
the end of two hours, 95.5° C. (204° F.), at which time the out- 
side of the meat was very much burned. It is evidently difficult 
on account of its poor conducting qualities to raise the temper- 
ature of a roast very much above the highest coagulating point 
of the proteids present. In one case the thermometer was left 
in the meat for thirty minutes after the maximum temperature, 
66.5° C. (156° F.), had been reached and at the end of that time 
it had fallen to only 60° C. (140° F.). The poor conducting 
power of meat has been discussed by Ostertag. ^ 

RISE OF TEMPERATURE OF THE INTERIOR OF 
MEAT DURING COOKING 

Although in the process of roasting, the meat is submitted 
to a temperature far in excess of that suitable for the cooking 
of proteid, it is evident that only a very thin outside layer of 
the meat is affected by this temperature. The temperature of 
the interior rises very slowly and follows the same rule as does 
the rise in temperature after removing from the oven. That is, 
the greater the difference between the temperature of the out- 
side and the inside of the meat, the greater is the rise of tem- 
perature. In the case of three of the roasts, the rise of tempera/- 

' Handbook of Meat Inspection p. 843. 

[293] 



10 

ture during cooking was noted at stated intervals. These ob- 
servations are tabulated in Table II. 



jTABLE II.— Rise op 


Temperature of 


Meat during Cooking. 






Time 
in the 
oven. 


Inner 

temperature 

of meat. 


Rise of 
temperature. 


Rise of 

temperature 

per min. 




Mins. 


°C. 


°F. 


°0. 


°F. 


"G. 


J, 


Roast No. 31 


30 

45 
60 
75 
85 

30 
45 
60 
75 
90 
100 

40 
55 
70 


24.4 
40.0 
52.2 
61.1 
66.5 

27.8 
44.4 
57.8 
68.9 
75.5 
79.9 

30.0 
39.4 
46.7 


76 
104 
126 
142 
152 

82 
112 
136 
156 
168 
174 

86 
103 
116 


"ih'.e 

12.2 
8.9 
5.4 








Roast No. 3 

Roast No. 3 

Roast No. 3 

Roast No. 3 

Roast No. 4 


28 
22 
16 
10 


1.04 
0.81 
0.59 
0.54 


1.87 
1.47 
1.07 
1.00 


Roast No. 4 

Roast No. 4 

Roast No. 4 

Roast No. 4 ' 

Roast No. 4 


16.6 

13.4 

11.1 

6.6 

3.5 


30 
24 
20 
12 
6 


1.11 
0.89 
0.74 
0.44 
0.35 


2.00 
1.60 
1.33 
0.80 
0.40 


Roast No. 1^ ;... 


Roast No. 1 

Roast No. 1 


9.4 
7.3 


17 
13 


0.63 
0.48 


1.13 

0.87 



1 Less fat than No. 4. 

" About one inch wider across the back than Nos. 3 and 4. 

It will be observed that the rise of temperature is more 
rapid during the earlier part of the cooking and decreases as 
the time of cooking increases. For example, in roast No. 3 in 
the period between thirty and forty-five minutes after going 
into the oven, the temperature rose at the rate of 1.04° C. per 
minute. In the last period of ten minutes, beginning seventy- 
five minutes after going into the oven, the rise in temperature 
was only 0.54° C. per minute. Or otherwise stated the rise of 
temperature was most rapid between 25° C. and 45° C. Be- 
tween 45° C. and 70° C. the rate of rise decreased and between 
70° C. and 80° C. it was still more gradual. In two cases (Nos. 
3 and 4) the rate of rise is very similar, except during the last 
period of ten minutes. The comparative rise of temperature 
in these cases is illustrated in Diagrams I and II. The differ- 
ence in the rise of temperature in Nos. 3 and 4 may have been 

[294] 



11 






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[296] 



13 

due to a difference in the temperature of the meat before going 
into the oven, which was not observed. It may possibly have 
been due also to a difference in the amount of fat. There was 
less external fat in No. 3 than in No. 4. Apparently fat tissue 
conducts heat more rapidly than does the muscular tissue- 
This statement has been made also by Grlage. ^ 

Drucker^ also mentions that uniformly lean meat is the 
most difficult to cook through. On the other hand Hoffman '' 
states that "the fat pieces of flesh are the more difficult to ster- 
ilize, the fat preventing a thorough penetration of the heat." 
This is in accord with the conclusions of various physiologists 
that fat is a poorer conductor of heat than is muscle fiber. The 
atter however are based upon the conductivity of fresh muscle 
fiber and may not apply under the conditions attending the ap- 
plication of heat during roasting. Since the proteids of the outqr 
surface of the meat are coagulated immediately upon going into 
the oven, the comparison as regards conductivity must be made 
between the fat and the coagulated muscle fiber. Hoffman' also 
mentions that the coagulation of the proteids makes the penetra- 
tion of the heat more difficult. Moreover the fat is capable of 
acquiring a higher temperature than is the lean which contains 
so large a proportion of water. 

It will be noticed in the illustrations that the small outer 
muscles, which are surrounded with fat, are cooked "well- 
done" even in the, case of the very rare roast (See Plate I), 
showing that to a depth of one or two inches from the back a 
temperature of more than 69° C. (156° F.) had been reached 
since at the latter temperature a little color should remain. 
A cut from the outside of the large center muscle of Nos. 1 and 
2 showed that from this direction, this degree of heat had pen- 
etrated not more than one-quarter of an inch, since that was 
the depth of the "well-done" crust. It must be remembered, 

' Ostertag- Wilcox, Handbook of Meat Inspection, p. 843. 
" Zeit. fur Fleisch- und Milch Hyg. v. 2, p. 21-24. 
' 2eit. tur Fleiach- und Milch Hyg. v. 13, p. 207. 

[297] 



14 

however, that the small muscle at the back is affected by heat 
conducted from two directions while the large center muscle 
is subjected to heat from one side only. 

The difference in the rise of temperature between Nos. 3 
and 4 is much less than that between No. 1 and either of the 
former. At the end of 75 minutes after being placed in the 
oven, No. 3 registered 61.1° C. (142° F.), while at the end of 
the same length of time, No. 4 registered 68.9° C. (156° F.), a 
difference of 7.8° C. At the end of 70 minutes, No. 1 registered 
only 46.7° C (116° F.), a difference of 14.4° C.as compared with 
No. 3, and of 22.2° C. as compared with No. 4. This was probably 
due to the fact that No. 1 was almost one inch wider across the 
back than the other samples. It seems probable that time and 
temperature being constant, the degree of cooking of a rib roast 
will be dependent upon (1) thickness from back to rib bone, 
(2) width across the back, and (3) degree of fatness. 

Certain characteristics of the different degrees of cooking 
are well shown by the illustration. One extreme is shown by 
the very full, plump appearance of the very rare roast, (See 
Plate I) indicating a minimum loss of both water and fat. This 
roast in which the maximum temperature reached at the cen- 
ter was 53.5° C. (128° F.) was very rare- throughout, apparently 
as much so as the most extreme taste would desire. By some, 
the roast illustrated in Plate II, in which the temperature at 
the center was 64.5° C. (148° F) might be called rare although 
it seems more properly to mark the beginning of the medium 
rare stage. This gives a range of 11° C. in which the meat 
might be cooked rare. 

The other extreme of medium cooked meat, having only a 
slight trace of pink remaining, is illustrated in Plate III. In 
this case the inner temperature reached 69° C. (156° F. ). This 
gives a range for medium cooked meat of only about 5° C. In 
Plate IV is seen an example of well-done meat in which all pink 
color is destroyed. The inner temperature of the center of 
this roast reached 78° C. (174° F.), giving a range of 10° C. for 
the well, done stage. In other words if the inner temperature 

[298] 



15 

of a roast is between 55° C. and 65° C. the meat will be rare; 
if it is between 65° C, and 70° C, it will be medium rare; and 
if between 70° and 80° C, it will be well done. 

The increase in the loss of water and fat as the degree of 
cooking increases, is shown by the drawing away of the flank 
muscles from the end of the bone. The outer layer of fatty 
tissue is gradually emptied of its contents, until in the very 
well-done roast it is principally a crisp layer of connective tis- 
sue, holding a comparatively small percentage of fat. 

THE INFLUENCE OF OVEN TEMPERATURE IN 

ROASTING 

Since the determination of the temperature reached' in the 
• center of the meat seemed to offer a reasonable basis for deter- 
mining and regulating the degree of cooking, a series of experi- 
ments was made to study the influence of the oven temperature 
in cooking meats to the three different degrees. The third and 
fourth standing rib cuts from animals about three years old 
were selected for these experiments. The roasts were as uni- 
form in size and character as could be obtained from the local 
market. Although unusual care was taken in this respect there 
was necessarily more or less variation in the character of the 
different samples. The meat was freed from bone, tightly rolled 
and secured with steel skewers. An incision was made to -the 
center of the meat with a sharp, narrow-bladed knife and a 
short chemical thermometer inserted in such a way that the 
bulb of the thermometer reached the center of the large muscle 
of the roast. 

Each roast was placed on the rack of an open dripping pan, 
the fat side being uppermost, so that the two cut surfaces were 
equally exposed to the oven heat. . In every case the meat was 
first placed in the oven at a temperature of 250° C. and this 
temperature maintained for fifteen minutes to sear the surface 
of the meat. The temperature was then reduced to the degree 
desired for the remainder of the cooking. This, for the high 
oven temperature, was 195° C; for the medium, 175° C; and 

[299] 



16 

for the low temperature, 100° C. For the longer part of the 
process, 195° G. seemed as high a temperature as could be used 
without causing excessive browning of the surface. The medi- 
um temperature was selected as representing a condition of the 
oven, familiar to most housekeepers for bread-baking purposes. 

With the low temperature, the objects were to use as nearly 
as possible the maximum temperature (83° C.) which is theo- 
retically suitable for proteid substances, and to produce, at the 
same time, the searing and browning of the outer surface, which 
is essential in well roasted meat. It having been demonstrated 
that when cooked at 83° C. the meat came from the oven gray 
and unattractive looking,' it was decided to raise the tempera- 
ture of the oven to 100° C. in these experiments. 

At the two higher temperatures the whole process was car- 
ried on in the oven of a gas range. For cooking at the low 
temperature the same oven was used for the preliminary fifteen 
minutes searing, after which the meat was transferred to the 
Aladdin ^ oven for the remainder of the cooking. In this oven 
it is possible to maintain an even temperature, and there is 
practically no oven ventilation. 

In order that the maximum inner temperature of the cen- 
ter after removal from the oven should approximate 55° C. for 
the rare, 65° C. for the medium rare, and 75° C. for the well- 
done meat it was found necessary to remove the roasts at 43° 
C, 55° C, and 70°C., when the temperature of cooking was 
either 195° C. or 175° C. When the temperature of cooking 
was 100° C. it was necessary, for reasons to be hereafter stated, 
to allow the inner temperature to reach higher degrees in each 
case before removal from the oven. 

In the first series of experiments, duplicate cuts from the 
right and left side of the same aniraal were roasted side by side 
under exactly the same conditions in order to test the method 
of cooking. After cooling over night the roasts were cut 
through the center and their physical appearance compared. 

' Univ. of 111. Agr. Exp. Sta. Cir. 71, p. 24. 
^ Atkinson's Science of Nutrition. 

[300] 



17 

Afterwards one roast was taken for analysis and the other 
tested for flavor, toughness, and so forth. The results of this 
series are tabulated below. 



TABLE III. Time of Cooking and Inner Temperature of Ddplicate Roasts. 



Cooking 

Experiment 

No. 


d 

1 

1 


Weight 
roast. 


« . 

fllO 

H 


: Temperature 
remainder 
of time. 


Total time 

of 
cooking. 


.3 c 

-" 3 
_ O 

s <^ 

O 

H 


Inner tempera- 
ture when 
removed. . 


a g 

II 






Lbs. 


Ozs. 


"C. 


°C. 


Hrs. 


Mins. 


Ming. 


°C. 


"C. 


169 
Duplicate . . . 


1833 
1834 


5 

4 


5.5 
11.0 


250 
250 


195 
195 




40 
35 


18.7 
20.2 


43 
43 


57 
58 


170 
Duplicate... 


1836 
1837 


4 
4 


7.75 
6.5 


250 
250 


195 
195 




35 
30 


21.1 
20.5 


43 
43 


53 
56.5 


Average. . 


(4).... 


4 


11.64 








35 


20.1 




56.1 


171 
Duplicate... 


1838 
1839 


3 
3 


5.0 
7.0 


250 
250 


195 
195 




35 

40 


28.6 
29.0 


55 
55 


62.5 
64.0 


172 
Duplicate. . . 


1840- 
1841 


5 
5 


7.0 
6.5 


250 
250 


195 
195 


2 
2 


30 
15 


27.5 
25.0 


55 
55 


61.5 
62.5 


173 
Duplicate . . . 


1842 
1843 


3 
3 


15.5 
13.75 


250 
250 


195 

195 


1 

1 


50 

55 


27.7 
29.8 


55 
55 


61.5 
62.5 


Average . . 

174 
Duplicate... 


(6). . . . 


4 


3.79 






1 


58 


27.9 




62.6 


1844 
1845 


5 
5 


2.75 
1.0 


250 
250 


195 
195 


3 
3 


00 
00 


34.7 
35.5 


70 
70 


74 
74 


175 
Duplicate... 


1846 
1847 


4 
4 


10.5 
11.25 


250 
250 


195 
195 


2 

2 


45 
30 


35.4 
31.8 


70 
70 


73 
73 


Average . . 


(4).... 


4 


14.37 






2 


49 


34.4 




73.5 









With the exception of the two roasts in Experiment No. 
169, the duplicates compared very closely in weight. In Cooking 
Experiments Nos. 169, 170, 171,andl7B there was a difference of 
5 minutes in the total time of cooking of the two roasts, and in 
Nos. 172 and 175 there was a difference of 15 minutes. The 
difference in the time of cooking per pound of the duplicate 

[301J 



18 

roasts, ranges from 0.4 in Cooking Experiment No. 171, to 3.6 
minutes in Cooking Experiment No. 175. In Experiments No. 
169 and 175 where the difference in the time of cooking was 
greatest, there was a noticeable difference in the degree of 
cooking of the two duplicates, those which were cooked for the 
shorter time per pound being less thoroughly cooked than their 
duplicates. This in both cases was due to a slight difference in 
the position of the thermometers in the roasts. In all other 
cases the duplicate, roasts compared very closely in the degree 
of cooking, as judged by physical appearance. 

TIME PER POUND IN RELATION TO DEGREE OF COOKING 

In the four roasts which were cooked to 43° C. (rare or un- 
derdone) at 195° C, the time per pound ranged from 18.7 min- 
utes to 21.1 minutes, averaging 20.1 minutes. In the six roasts 
which were cooked to 55° C. (medium), the time ranges from 
25 minutes to 29.8 minutes per pound, averaging 27.9 minutes- 
In the four roasts cooked to 70" C. (well-done) the time varied 
from 31.8 minutes to 35.8 minutes, averaging 34.4 minutes per 
pound. 

This rate per pound is considerably greater than the rate 
necessary to cook the single short rib roasts (not rolled) used 
in the previous experinaents. In the latter case (Table I ) only 
16.3 minutes per pound were required to cook the meat rare 
(46.5° C), 19.2 minutes per pound to cook it medium (60° C.) 
and 34.4 minutes per pound, very well done (79° C). This is 
no doubt due to the difference in shape and size of the two 
kinds of roasts. In the rolled roasts the meat is in a much 
more compact form than it is in the short rib roasts. The dif- 
ference in the number of minutes required per pound in the 
two kinds of roasts isillustrated in Diagram III and Tables No. 
I and IV. 

RISE OF TEMPERATURE AFTER REMOVAL FROM OVEN 

The rise of temperature in the rolled roasts after removal 

from the oven followed the same rule as in the short rib roasts. 

[302] 



19 




[303J 



20 

TABLE IV. Time op Cooking and Inner Tempbeatube of Roasts at Diffeeent 

Oven Temperatures. 



umber of 
elxperiments. 



0) a 

ag 



Average of 4 
Average of 2 
Average of 2 

Average of 8 
Average of 5 
Average of 4 

Average of 4 
J^fverage of 2 
Average of- 3| 



°0. 



195 
175 
lOU 

195 
175 
100 

195 
175 
100 



« ^ > 



sa 



°0. 



43 

43.8 

56 

54.9 
55.4 
62.1 

70 
70 

72.7 



ag 



°c. 



56.1 
55.8 
58 

62.9 
63.5 
63.9 

73.5 
74.3 
72.7 



Rise of 

inner 

temperature. 



Maxi- 
mum. 



°C. 



15 

12 

2 

10.5 
10 
2.5 

4 
5 



Mini- Aver- 
mum. I age. 



0. °C. 



10 

12 

2 

6.5 

7 

1.5 

3 
3.5 



13.1 
12 
2 

7.9 
8.1 
1.8 

3.5 
4.3 



Time 

of 

cooliing. 



Maxi- Mini- 
mum, mum. 



Mina. Mina 



21.1 
18.4 
39.7 

29.8 
30.6 
44.3 

35.5 
33.4 
89.6 



18.7 
18.1 
37.3 

21.8 
22.9 
41.4 



Aver- 



Mins. 



20.1 
18.3 
38.5 

26.5 
26.0 
42.8 



31.8 34.4 

29.3 31.4 

69.4 79.8 



Condition 

of 

Meat. 



Rare 
Rare 
Rare 

Medium rare 
Medium rare 
Medium rare 

Well done 
Well done 
Well done 



That is, the lower the inner temperature of the meat when re- 
moved, the greater was the rise after removal. This rise of 
temperature was however greater in every instance in the 
lulled, two rib roasts than in the short, single roasts. When 
removed at 43° C, the average rise in the rolled roasts was 
13.r C, while in the single roasts removed at 46.5° C, it was 
7.5° C. At 65° C, the average rise in the rolled roasts was 7.9° C, ' 
Airhile at 60° C, in the short rib the rise was 4.5° C. The com- 
parative rise of the inner temperature in the two kinds of 
ipasts is shown in Diagram IV and Tables No. I and IV. 
i The difference in the rise of temperature in the two cases 
i^ seen to be greatest at the lowest temperature. Above 55° C. 
the rise in the two instances follows almost parallel lines. 

[ j iNPLUENqE OF TEMPERATURE OF CoOKI^G UPON RISE IN InNER 

I Temperature after Removal prom Oven 

i The rise of the inner temperature after removal from the^ 

[304] 



21 



OIM~<^ <J>^0 f^^ 






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p 






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[305] 



22 

oven is dependent upon the temperature at which the meat is 
cooked as well as upon the inner temperature of the meat. In 
Table IV is shown the maximum, minimum, and average rise 
of temperature upon removal from the oven, when cooked at 
the different temperatures. This data is also illustrated in 
Diagram V. 

The average rise in temperature ranges from nothing in 
the roasts cooked well-done at 100° C. to 13.1° C. in the roasts 
cooked rare at 195° C. When the roasts were cooked rare at 
176° C, the rise of inner temperature is but one degree less than 
in those equally cooked at 195° C. 

In the well-done and medium rare roasts, the rise at the 
two higher cooking temperatures is very nearly equal. At 
100° C. the rise of temperature was the same whether the meat 
was cooked rare or medium rare. Because of the small rise of 
temperature observed in the roasts cooked at 100° C, it was 
found necessary to raise the inner temperature of the meat to 
a higher degree before removing from the oven so that the max- 
imum temperature after removing from the oven should cor- 
respond more nearly with those in the other cases. 

The lines showing the rise of the inner temperature in the 
medium rare and well-done roasts are nearly parallel. The 
rise of temperature in the rare roasts shows a marked diver- 
gence from this parallel. 

A similar rise of temperature was noticed by J. Lawrence 
Hamilton,' who says that in large joints there may be a rise of 
30° F. 

INFLUENCE OF OVEN TEMPERATURE UPON LENGTH 
OF TIME OF COOKING 

When the oven temperature was only 100° C, the number 
of the minutes per pound required to produce the same degree of 
cooking was, as was to be expected, considerably greater than 
the time required at either of the higher temperatures. At 
175° C, however, the time of cooking per pound is found to be ac- 

^ Lancet 1894, Dec. 8, p. 1376. 

[306] 



23 



s 


?>,--^>^^i> c>,s\-ssa^"^^r5'S 






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[307] 



24 

tually less than that at 195° C. In only two cases was the time 
of cooking per pound at the latter temperature lower than in the 
corresponding series at 175° C. A comparison of the length of 
titiie required to produce the same results is made in Table IV 
and Diagram VI. 

At 100° C, the average time required for the rare roasts 
was 38.5 minutes per pound, for the medium rare roasts 42.8 
minutes, and for the well-done 79.8 minutes per pound. At 
195° C, the average time for the rare roasts was 20.1 minutes, 
for the medium rare 26.5 minutes, and for the well-done 34.4 
minutes. 

The slightly longer time required at 195° C. than at 175° C. 
may be due to the fact that at this temperature the outer crust 
is so hardened and dried that it becomes a poorer conductor of 
heat. In Diagram VI, it may be seen that the increase in the 
number of minutes per pound required for the medium and 
rare roasts at the different oven temperatures follows almost 
parallel lines. This is true also of the well-done roasts when 
cooked at 195° C. and 175° C, but from this point to 100° C. 
the line diverges considerably. Apparently it is much more 
diflScult, at the latter temperature, to raise the temperature of 
the interior of the meat from 60° C. to 70° C. than it is to 
raise it from 50° C. to 60° C. 

' Eesults of Roasting at Different Temperatures 

I The physical characteristics of the roasts cooked at different 
temperatures are also of importance. In general it may be 
said that the lower the temperature of the oven, the more uni- 
foi-m will be the condition of the interior of the meat. Even 
in those roasts cooked medium rare in the Aladdin oven at 
10p° C, the pink coloration extended almost to the surface of 
th|e meat. 

i At all of the temperatures used, the meat was well browned 
and attractive looking. The temperature of 100° C. in th§ 
Aladdin oven proved therefore to be suflBcient to retain the 

[308] 



25 



Q 
o 



t 



§ 



^ 



iS- 




^?' 8| 






^ 



^ Qi 




'^ $^ 


^ ^ 


^ ^' 




n 




k o> 


<^ 1 


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51^ 

II 
11 



z 
1 

r 
c 
p\ 
z 
o 
PI 

o 
■n 

o 

<; 

2 

i^ 

S 
D 



ri G^ 












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c 

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3 

2 

rl 

s. 
m 

o 

■n 

o 
o 

X 

z 








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S!^ ^ & S! § 5 ^ ^ Is 



[399] 



26 

browning produced by the preliminary searing. At 195° C. 
there was some tendency to over-browning, especially when 
the roasts were cooked well-done. At the latter temperature 
also the well-done layer is somewhat deeper than in the meat 
cooked at 175° C. 

In a test made by cooking duplicate samples from the 
same animal, one in the gas range oven at 195° C. and the oth- 
er in the Aladdin oven at 100° C, it was agreed that the latter 
gave the best results in regard to the flavor and juiciness of the 
meat but that there was little difference in the tenderness of 
the two roasts. The roast cooked in the gas range seemed 
more compact and closer in texture and was noticeably drier 
in the lean part than that cooked in the Aladdin oven. 

There is a marked difference in the character of the drip- 
pings in the three cases. At 195° C. the color of the melted 
fat in the drippings ranged from a deep crimson to a topaz yel- 
low. Upon cooling these became lighter in color but were still 
very much darker than the drippings produced at 175° C. which 
were almost white. The drippings produced in the Aladdin oven 
were very scanty in amount, the fat was very light colored, 
and there was a variable quantity of watery juice. 

To produce the most desirable flavor if the drippings are to 
be used as gravy, a comparatively high temperature is probably 
necessary. It is desirable however to avoid a temperature suf- 
ficiently high to cause excessive decomposition of the fat, which 
is indicated by the deepening in color, since these decomposi- 
tion products are irritating and may cause digestive disturb- 
ances. 

SUPPLEMENTARY EXPERIMENTS 
In order to secure further information upon some of the 
questions raised by the preceding experiments, it was thought 
desirable to repeat a few of the typical cases in order to ob- 
serve the temperature in different parts of the rolled roasts. 
For this purpose the same cuts were used as in the previous ex- 
periments, namely, the third and fourth ribs. These were pre- 

[310] 



27 

pared for cooking exactly as before by boning and rolling. Two 
pairs of the roasts, Nos. 5 and 5a and 7 and 7a were duplicates 
from the right and left side of the same carcass. The remain- 
ing pair, Nos. 6 and 6a, differed considerably in size and weight, 
and serve best to illustrate the difference in time required, ac- 
cording' to the weight of the roasts. The weight, dimensions, 
and time of cooking of the six roasts are given in Table V. All 
of these roasts except No. 6 were from heavy and apparently 
quite mature beef. 

TABLE V. Weight, Dimensions, and Time op Cooking Two-kib Rolled Roasts. 





Description of roast. 


Temperature 
of oven. 


Time of cooking. 


Inner' 
temperature. 


Ex- 
peri- 
ment 
No. 


Weight. 


Diam- 
eter. 


Width 
across 
back. 


During 

first 

15 

minutes 


During 
remain- 
der. 


Total time. 


Time 

per 

pound 


When 
re- 
moved. 


Maxi- 
mum 
after re- 
moval. 




Lbs. 


Ozs. 


Ins. 


Ins. 


°C. 


°C. 


Hrs. 

2 
2 

2 
3 

4 
4 


Mns. 


Mins. 


°C. 


°0. 


5 

5a.... 

6 

6a.... 

7 

7a.... 


7 

7 

4 

7 

6 
6 


4 

7 

7 
14 

0^ 
6 


5Jx7i 

4Jx6i 
5Jx7i 

5}x7i 
4ixCf 


6i 
6i 

5 
6i 

6} 
6i 


250 
250 

250 
250 

250 
250 


195 
195 

175 
175 

100 
100 


45 
43 

00 
00 

10 
30 


22.7 
21.8 

27. 
22.9 

41.4 
42.2 


54 
55.5 

55 

57 

62 
62 


64.5 
64 

64 
64.5 

63.8 
63.5 



The experiments were made in duplicate, two roasts being 
cooked medium rare at each of the three oven temperatures 
previously used. Three thermometers were inserted in each 
roast. One was placed as before at the center, a second about 
a quarter of an inch under the outer surface, and the third 
half way between these two. The bulbs of the three thermom- 
eters were directly in line with each other. The temperature 
was observed, during the cooking, at fifteen minute intervals 
and at five minute intervals after removal from the oven, until- 
the maximum temperature was reached. 

TEMPERATURE OF THE INTERIOR 
The inner temperature observed in each roast is recorded 

[311] 



28 

in Table VI, (page 31) the rise of temperature for each set of 
duplicates being plotted in Diagrams VII, VIII, and IX. The 
rise of temperature observed in similar portions of the duplicate 
roasts is quite uniform in all cases except those cooked at 175° 
C. The weight and dimensions of these two roasts were quite 
different and the rise of temperature in the smaller roast was 
more rapid. 

As a result of the preliminary cooking for fifteen minutes 
at 250° C. there was an immediate and considerable rise of the 
temperature near the surface. According to Table VI and the 
accompanying diagrams it may be seen that this initial rise 
ranged from 34° C. in Roast No. 7 to 13° C. in Roast No. 6a. In 
the latter instance the thermometer was however more deeply 
imbedded in the meat than in the other cases. 

The temperature at the center of the meat was very little 
affected by this first heating but after this period the tempera- 
ture of the interior rose at a more rapid rate than did that of 
the exterior. The rate of rise at the intermediate point was 
about the same as that at the center. 

The difference in the uniformity with which the roasts are 
cooked under these various conditions is shown by the varia- 
tions in the temperature at the three points. In the roasts 
cooked at 195° C. the difference in temperature between the 
center and intermediate point when removed from the oven 
averaged 9° C. Between the center and the surface the aver- 
age difference in temperature was 25° C. The differences in 
temperature in the roasts cooked at 175° C. were, between the 
center and intermediate point 5° C, between the center and 
the surface 13° C. In the roasts cooked at 100° C. the variation 
in the temperature between the center and the intermediate 
point was 1° C. and between the center and the surface 5° C. 
It is evident that since in the roasts cooked at the lower tem- 
perature the degrees of heat reached in the different portions 
are very similar, the meat will be found in very nearly the 
same condition throughout. 

It is interesting to note that a slight difference in the tem- 

[312] 



29 










[313] 



30 




L314] 



31 



TABLE VI. Inner Tempehatdee in Two-Eib Rolled Roasts. 







Cooked at 195° oven temperature. 


Cooked at 175° C. oven temperature. 


Cooked at ]00° C. oven temperature. 


Length of 
time. 


Temperature 
at center. 


Temperature 

of the 
intermediate 

flesh. 


Temperature 

near 

surface. 


Temperature 
at center 


Temperature 

of the 
intermediate 

flesh. 


Temperature 

near 

surface. 


Temperature 
at center. 


Temperature 

of the 
intermediate 

flesh. 


Temperature 

near 

surface. 




Ex- 
peri- 
ment 

5. 


Ex- 
peri- 
ment 
5a. 


Ex- 

peri- 

ment. 

5. 


Ex. 

peri- 

ment 

5a. 


Ex- 
peri- 
ment 
5. 


Ex- 
peri- 
ment 
5a. 


Ex- 
peri- 
ment 
6. 


Ex- 
peri- 
ment 
6a. 


Ex- 
peri- 
ment 
6. 


Ex- 
peri- 
ment 
6a. 


Ex- 
peri- 
ment 
6. 


Ex- 
peri- 
ment 
6a. 


Ex- 
peri- 
ment 

7. 


Ex- 
peri- 
ment 
7a. 


Ex- 
peri- 
ment 

7. 


Ex- 
peri- 
ment 
7a. 


Ex- 
peri- 
ment 

7. 


Ex- 
peri- 
ment 

7a. 


Hrs. Mina. 
(a) In oven. 


"C. 


° C. 


°.o. 


° C. 


° C. 


° 0. 


° C. 


° C. 


° C. 


° 0. 


° C. 


° C. 


° C. 


° C. 


° C. 


" C. 


° C. 


° 0. 






11.5 


8 


11.5 




12 

40.5 

47 

52.5 

57 

60 

64 

68 

70 

75.5 

79 

79 


'46'. 5' 
55 
60 
68 
71.5 
75.5 
76 
78 
80 
81 
81.5 


18.5 

19 

20 

23 

28 

34 

41 

48 

55 


15 

ig'.s 

24 

28 

34 

38.5 

44 

47 

50.5 

57 


18.5 

21 

25.5 

31 

37.5 

43 

50 

56 

61.5 


15 

'26' ' ' 
23 
29 
34 
40 
44.5 
49 
54 
56 
61 


18.5 

36.5 

41.5 

46.5 

53.1 

56.5 

61 

66 

69.5 


16 

29.5 
36.1 
41 

4.T 

50 
53 
56 
58 
60 
62 
64 
66 


18 


12 


18 

20 

22.5 

27 

31 

35 

38 

40 

44.5 

47.5 

50 

52.7 

55.5 

57 

59 

60 

62 

62.5 

62.8 
62.8 
62.8 
62.2 
62 


12 


15'" 

19 

24.5 

28.5 

33.5 

37 

41.5 

44 

47.5 

50 

52.5 

55 

57 

59 

60 

62 

63 

63 

63.7 

64 

64 

64 

64 

63.2 

62.5 


18 
52 
53.5 
55 
53 
51 
56 
58.5 
59.5 
62.5 
63 
65 
66.5 
64.5 
66 
68 

67.7 
65 


52.8 

48 

44.5 


-^- — - 




15 
30 
45 
00 
15 
30 
45 
00 
15 
30 
45 
00 
15 
30 
45 
00 
15 
30 

ter re- 
cal. 

5 
10 
15 
20 
25 
30 
35 
40 
45 
50 
55 
60 


16 








14.5 

18 

24.5 

30.5 

36 

44 

49 

55 

60 

65 


■2i'" 

29 

35 

40.5 

49 

55 

59 

63 


'26'" 
22 
25.5 
29.5 
33 
37 

40.5 
44,5 
47.5 
50 
53 
55 
57 

59.5 
61.5 
62 


'u" 

16.2 

20 

24 

28.5 

32 

36.8 

40 

44 

47 

50 

52.5 

55 

57 

59 

61 

62 

62 

62.5 

63 

63 

63.5 

63.5 

63.5 

63 


47 








54 


1 
1 
1 
1 
2 
2 
2 
. 2 
3 


'23""" 
26 
32 
37 
43 
48 
54 


15 

20 

25.5 

30 

39 

45 

51 

55.5 


52 

54 

55 

57 

58 

60.5 

62 

64 

65 

64 

65 

65 

67 

67 

69 

69 

59 

53.5 

51.5 

47 

46 

45 

43.5 

42.5 


3 
















3 


























3 


























4 




1 


















... . . 


4 




1 




















4 




1 




















(b) Af 
mo 


55.5 

56.5 

59 

60 

61.5 

62.5 

63.5 

64 

64.5 

64.5 


56 

57.5 

59 

60.5 

61.7 

62.4 

63 

63.5 

64 

64 

64 

63.5 


65.5 

66.5 

67.5 

67.5 

67.5 

67 

66 

65 

64.5 

63 


68.5 

64.5 

64.5 

64.5 

64 

63.7 

63 

62 

61.5 

60.5 

69.5 

58.8 


68 

59 

53 

50 

47.5 

46 

43.5 

42.5 

42 

41 


64 

57 

51.5 

47 

44.5 

43.2 

41.5 

40.5 

39.8 

39 

38 

37.5 


56 

58 

59 

61 

62.5 

63.5 

64 

64 

65 

65 

64 

64 


57.5 

58.5 

59.8 

61 

62 

63 

64 

64 

64.5 

64.5 


62.5 

63 

64 

64 

64 

64 

63.5 

63 

62 

61 + 

61 

60 + 


61 

63 

64 

64.5 

64.5 

64.5 

64 

63.8 

63.5 

62.5 


62.5 

60 

58 

55.5 

54 

52.8 

51.5 

50 

49 

48 

48 

47 


64 

62 

59 

55.5 

55 

53 

51 

50 

48.5 

47.5 


62 

62.8 

63.3 

63.8 

63.8 































































[315] 



33 




[317] 



34 

perature of the roasts before going into the oven does not exert 
a marked difference upoti the subsequent rise of temperature. 
For exattiple, thfere was a difference of 6° C. between the tem- 
perature of the centers of Nos. 7 and 7a before these were placed 
in the oven, but this difference gradually diminished until it 
was reduced to but 1° C. fifteen minutes before the latter was 
removed froln the dven. The same fact is shown in the roasts 
cooked at 195° C. Here there wats a difference of but 3° C, in 
the initial temperature but that which had the lower tempera- 
ture Ett the beginning rose above the other during cooking. 

A comparison df the averages of the temperature at the 
centers df the duplicate roasts (See Diagram X) shows that at 
100° C. the temperature during the first hour of cooking rose 
the most rapidly. After the first hour the rise was most rapid 
in the roasts cooked at 195° C. During the whole time the rise 
of temperature at 175° C. occupies an intermediate position. 

The same diagram illustrates Gae difference in the rate of 
rise of the temperature of the single shott rib and the rolled 
rib roasts. The average weight of the former was 3| pounds 
and of the latter 7 pounds. The time required to attain a tem- 
perature of 55° C. at the center df each was one hour for the 
former and two and three-fourths hours for the latter. Hence 
it is evident that the size and shape of the roast has a marked 
influence upon the time required. The greater amount of sur- 
face exposed by the single short rib roast in proportion to its 
cubic contents makes it possible for the heat to penetrate to 
its center at a much more rapid rate than in the rolled roasts. 

The difference in the time required to cook two roasts of 
the same character but of different weights is illustrated by 
Nos. 6 and 6a. The former weighing 4 lbs. 7 ozs, required at 
the rate of 27 minutes per pound and the latter weighing 7 lbs. 
14 ozs. but 22.9 minutes per pbund to reach the same degree. 
It may be said in general that other things being equal the 
heavier the roast, the less will be the time per pound required 
to cook it. 

After the roast is removed from the oven the temperature 

[318] 



35 



•V >• (m JM (i| 

-Q, '^ <> «>i 5 

' O * ■ I ■ l ' L 



■UIU- 




t 



[319] 



_| 



36 

of the exterior drops immediately, the most rapid fall occurring 
during the first fifteen minutes, after which it is more gradual. 
The temperature of the center rises slowly and steadily during a 
period of from 30 minutes in the roasts cooked at 100° C, to 45 
minutes in those cooked at 175° C, or 195° C. As before stated 
the rise is greatest when the cooking has been carried on at 
the latter temperatures. The temperature at the intermediatie 
point rises slowly for from 15 to 30 minutes after removal from 
■the oven and then falls very slowly. ; 

In this supplementary set of experiments the only roast 
(No. 6a) cooked at 175° C. which can be compared with thosie 
cooked at 195° C. required about the same time per pound, the 
rise of temperature being a little more gradual. 

CONCLUSIONS 

As a result of the foregoing observations it nlay be con- 
cluded: 

1. That the conditions of the interior of a roast may b0 
quite accurately determined and therefore the degree of cook- 

. ing controlled by observing the temperature reached in thje 
' center of the meat. 

2. That, except in the case of the roasts cooked well-done 
at 100° C, there is always a rise of temperature in the center 

: of the meat after being removed from the oven, when cooked 
under the conditions of these experiments, if the meat is not cut. 

3. That this rise of temperature depends upon (1) thie 
temperature of cooking and (2) the temperature of the interior 
of the roast when removed from the oven, (3) the size and 
shape of the roast. 

4. That the number of mintites per pound necessary to 
produce a certain degree of cooking depends upon (1) the char- 
acter of the cut as regards size, shape, etc., and (2) the temper- 
ature of the oven. For example, a single short rib roast con- 

I taining the, bone required 16..3 minutes per pound to cook the 
meat rare, while the two-rib rolled roasts averaged 20.1 minutes 
at the same temperature to reach the same condition. 

[320] 



37 

5. That the roasts are as quickly cooked at 175° C; as at 
195° C. This is important from a practical stand point as it 
involves a question of economy in fuel, especially if gas is the 
fuel used. 

6. When cooked at 100° C, a very much longer time is re- 
quired to raise the inner temperature from medium (62° C.) 
to well-done (72° C.) than to cause the same rise at 195° 0. or 
175° C. There is therefore very much less danger of over-cook- 
ing the meat at this temperature (100° C). At the higher 
temperature a very few minutes over-cooking may be sufficient 
to carry the inner temperature above the desired degree. 

7. That the lower the temperature of cooking, the more 
uniform is the condition of the interior of the meat. 

8. That by any of the methods of cooking used in these 
experiments an attractive appearance is produced. 



r:-!211 



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